Haven't been around in quite a while... life's changes have kept me from enjoying my favorite website as much as I used to. Good to see the site is going strong and growing!

Anyway... I've had an ongoing "check engine" light issue for well over a year now. I've checked gas caps, and taken it to the dealer every time. They have always been genuinely concerned and tried their best, but after a few days to a month, the telltale "ding!" and light shows up again. I'm getting increasingly frustrated.

I know they have cleaned the throttle body, and checked numerous things... the most recent service was replacing some major computer module. That was two weeks ago, and within two days of the new module installed the light was on again (and it hasn't turned off since). I am out of warranty by a few thousand miles (bought my 07 before Jeep implemented the full warranty) but thankfully the Service Manager has been aware of my issue and because it was happening long before I was out of warranty, they've been working on it for free as if it were still under warranty. I didn't pay a cent for that expensive computer module... nice of them, of course... but I want my Jeep fixed!

I will try turning the ignition key trick today to see if it will pull a code...

I was curious to know if ANYONE actually had a solution to their check engine light. I've read through all the other threads but most of them never posted a solution.

Or buy the scan guage which offers code reading as well as other goodies

the code is the key and the vendor codes even more useful. See if any of your friends has the code reader that reads ABS as well as vendor specific codes. I suspect you are seeing the standard code supplemented by a vendor code which the inexpensive readers will not pick up.

There are several relating to MIL (Malfunction Indicator Light) and they give the codes involved. Once you find out the code, you may hit on the problem. Hope this reference helps you out. I was going to suggest having the PCM software updated but if it was completely exchanged, it should have been taken care of. Unless of course, the new PCM has the same outdated software. Might be worth a check.

Each June and October, I get the old chime with the MIL engine check lite or a GasCap lite. Each time, my Scangauge shows a Diagnostic Test Code (DTC) as P0455. This is an annoyance that I have learned to deal with and fix on each occurance.

In fact, I am experiencing the MIL Kabuki dance now. The P0455 code is the gas tank emission sensors bitching. In my case it is caused by large change in outside temperature (in June & October). The remedy is annoying but simple... see link...

Thanks guys... I've never pulled the codes as I don't have a reader. Each time, I've just taken it to the dealer. I'll try the key code thing today and see if it gives me anything. No strange symptoms or engine running badly. Just that annoying light on most of the time.

Allo AZCycle, I share your frustration on the MIL chime. The MIL chime happened to my Riot within 2 weeks of new delivery in June 08. It freaked me out. Looking back, my Jeep showed no abnormal symptoms or performance problem while the chime MIL comes on. All told, the MIL (sometimes GasCap lite) came on a total of half dozen days.

Next time you are at your friendly dealer, ask them for the code.

My P0455 code problem was caused by some over-sensitive emission sensor during days of large swings in outside temperature/humidity. I normally use a lockable MotoRad gas cap. It works 97% of the time without chime problem. When the MIL comes on, I just replace it with the OEM cap: The MIL disappears after a day or so. Then put the MotoRad gas cap back on with no silly MIL for months until the next set of weather swings.

In my case, there may be a slight fitment problem with my MotoRad cap. Other members using MotoRad caps reports no problem. I may have bought a quirky cap; or my gas tank fill-nozzle don't like my particular MotoRad cap under certain atmospheric conditions. Who knows?! I don't care any more.

In fact, another member PatriotPierre from Quebec reported similar MIL problem in the depth of winter. Quebec gets first dibb on Arctic blasts; Maine get only second hand chill after Quebec

I wonder if your OEM gascap have occasional fitment problem. Cost you a few dollars for an after-market cap to find out. You mind as well spurge $20 for a lockable cap. May foil gas-thieves when high gasoline prices returns.

Finally, when does your MIL comes on, for how long? When does it disappear?

Sorry for the late response... been crazy busy! Well I attempted the ignition key-turn and it didn't work for me... no codes displayed. But I did go out and release the stock gas cap, and cranked it down again. Sure enough, 30-minutes later the check engine light went off. That got me thinking. We DID have a weird change in temperature here that coincided with the check engine light and we went on a trip to northern arizona with much cooler temps.

About a week later, the gas tank was low, and the low-fuel light came on. Soon after (within a few hours) the check engine light came on. I filled up the tank, making sure to tighten the gas cap well, and the engine light went off. It's been off for about a week now.

So I'm really starting to think it might be the gas cap and/or change in pressure/temperature, etc. Next time I take the Jeep in for it's oil change, I'll have them pull the codes and tell me what they are. In the meantime, I'm just going to keep experimenting with the gas cap. I want to get a lockable cap anyway...

Hi, I am new to the forum so not sure if I'm posting correctly or in the right place!

Found this site b/c I was wondering if anyone has been having the same problem and if anyone has any idea of how to rectify and/or if there is any recourse to this.

Pending my next phone call, I will be taking my 2007 Jeep Patriot into the dealer for the FOURTH time for the same problem...the engine light keeps coming on (not flashing, thank goodness). The first time they told me it was a computer reload/update issue and it would be solved. A couple weeks later, it came back...I took it back in, and this time they told me I hadn't turned the gas cap tightly enough. This is hard for me to believe, because I am a religious five-time cap turner (and I am now a TEN-time cap turner). This time they also said there was a fuel vapor leak. A couple weeks later, the light came back again...took it in and they told me it was the gas cap again. I still can't believe that is possible, unless the cap is loosening itself?? Ironically, a couple weeks later a light came on that said "gas cap"-- a lot more appropriate, however- still hard to believe as I've screwed it on ten times. I took off the cap, rescrewed it, restarted, and the light went away. And now, another couple weeks later/just yesterday, the engine light came on again.

I am beyond frustrated as the dealer is 40 minutes away from me; they do not give loaners, so I need to get a ride to and from every time; and I cannot keep taking time off of work to get this done! Even though it's under warranty (for another few months)--- it is a complete nuissance...and worse, what happens one day when I think it's the gas cap, but it's really something more serious pertaining to the engine?

After reading through other posts, perhaps I should mention that I also have the problem with water leeking through the back door after it rains, and also my ignition hesitates to start. I took it in the for ignition problem once before (this was mid-summer so it was not cold or anything)...theytold me they reset the computer and it should be fine. It still hesitates.

Also a tad disturbed to hear that Jeep is no longer making the Patriot.

TTM, and AZCycle: I'd try replacing the gas cap or at the very least, wipe down the O-ring seal and the top of the filler neck (though there is a one-way vent valve built into the cap to allow fresh air into the tank as the fuel level drops and this could be leaking as well). Perhaps some dirt is preventing a tight seal?

TTM: As for the ignition problems, how many miles do you have on it and if close too, or over 30k miles, have you replaced the spark plugs? The patriots didn't come with platinum plugs and need to be replaced every 30k miles. Also, check your air filter while you're there and replace that as needed.

Well another update: Seems replacing the computer didn't do anything. The light has come on a few times since the replacement. Each time, we've had a drop in outside temperature or it came on along with the low-fuel light. Opening the gas cap and re-tightening seems to be working.

However. While my fiance was driving yesterday, the check engine light came on and the Jeep immediately stalled. It restarted fine and acted normal. She did the gas cap trick and the light went off right away.

But the stalling concerns me, so we took it into the shop this morning and explained everything. I asked what code the computer has been showing and teh service manager said it was a "camshaft position sensor" code since day one. So I don't know what to think. The error codes don't show that it is a fuel/vapor/gas cap issue but the light responds to tinkering with the light.

The camshaft position sensor went out on my 94 Ford Ranger years ago, and it cost me $1000 to fix... they had to tear apart half the engine to get to it.

On a related topic, we're selling the Patriot. I can't afford the payments anymore with a new mortgage and a wedding to pay for next year. Refinancing really doesn't help unless we extend the term and I'm not going to do that. We're going to sell it and buy a less expensive used vehicle. I'd like to get this check engine light issue resolved so the new owner doesn't inherit it.